Chocolate

Why you just don’t see some things made from scratch.

I have to admit: I have a penchant for making things from as fundamental and raw ingredients as possible. While some people like to prepare from scratch for special occasions, I tend to do it for that rare occasion called “Tuesday”. I can certainly cook, and I enjoy it, but there’s something of the engineer in me that likes the precision of activities like baking, where the process is a bit more rigorous. There is a healthy population of people who are like me in this respect: homebrewers fuss over wort temperatures and measures of liquid gravity, artisanal bakers make their own sourdough bread from carefully maintained cultures, micro chocolate makers fuss over the perfect blend of terroir in their cocoa.

OK, that last one is a bit more esoteric than the others, but that hobby really does exist. I know from experience: I do all of those things. Yep, that’s me. Food nerd.

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Tuesday

The chocolate got started when I mentioned to Laurie in passing that I don’t know how chocolate is made, but I would be interested to learn. I should have realized the consequences of such a statement. Laurie, Enabler of Strange Projects, took that one innocent comment and pushed me headfirst into chocolate maker status by procuring the ultimate chocolate making birthday kit: some research books, raw ingredients, and enough simple tools to experiment – and I haven’t looked back.

The basic idea behind chocolate is to take some beans from the cocoa tree (theobroma cacao) and combine them with other ingredients like sugar, vanilla, and possibly milk. Grind them all together until you get a thick, smooth liquid, and pour the liquid into molds to solidify. Much more detail about this process later, but that’s the gist.

That first batch of chocolate was made with some store-bought cocoa nibs and sugar in a mortar and pestle. It was barely – and I mean just barely – recognizable as chocolate, but it was enough for me to get some wild ideas. A shocking number of things can be made at home using equipment you already have. Chocolate is not one of those things, unless you happen to possess the machinery to work your mortar and pestle for days at a time. Thankfully, there are other curious people in the world who blazed this trail: after some research, I turned up a guy who created this site, Chocolate Alchemy; he’s also gotta be an engineer. Apparently we do strange stuff like this. The site is a great resource if you are interested in making your own chocolate; you can get everything you need to get started: equipment, raw ingredients, tools, and information.

I buy my beans from him, since getting raw bulk cocoa beans is a bit of a challenge. Chocolate, like many valuable agricultural products, tends to be traded on a commodity market. It is very similar to coffee in this way – the producers of the good will negotiate in the market for the price, then deliver it to (or have it picked up by) the seller. The seller then will either distribute the good or resell it to a distributor or wholesaler, who takes a cut for absorbing the risk from the price fluctuations on the supply side. This is more or less the way most specialty or luxury agricultural goods, like chocolate, coffee, and spices, find their way from producers to the market.

Due to the way this all works, wholesalers very rarely sell small quantities directly to the public, especially in an industry like cocoa, where the majority of buyers are fairly large maufacturers who make chocolate. Because of this, Chocolate Alchemy’s store is a great place to buy cocoa – I don’t know how they get their beans, but that’s the point. I don’t want to put up with the hassle of sourcing the beans in units of tons, and, while chocolate is popular with the wife, I don’t think she wants a dump truck of unprocessed beans in the closet.

The “beans” are really the seeds of a fruit-bearing tropical tree that has been prized since ancient times for the flavor of its fruit and seeds. There are generally three types: Forastero, the plebian but resilient ”regular” strain of chocolate; Criollo, the delicate patrician “elite”, and Trinitario which is, despite its name, a hybrid of the other two types. Regardless, cacao has pretty much always been valuable; in fact, in the Aztec empire, cocoa beans were used as a form of currency and tribute. Thankfully, today we use chocolate as a tribute to our loved ones, instead of inheriting some of the other rituals of the Aztecs.

Cacao only grows in the tropics: it seems that it originated in the Amazon river basin near the Andes, but it has been domesticated and spread throughout the world. It is pollinated by tiny midges instead of the usual bees, and tends to grow best under shade, with lots of humidity, and good soil. It’s fussy. The flowers produce a fist-sized football-shaped fruit pod, which is itself reputed to be very tasty, but which rots almost immediately upon harvest, which is why you can’t pick it up at a Whole Foods near you.

The pods are harvested by hand and put in piles and left to rot. While the fermentation process adds some tanginess and acidity to the flavor of the seeds, the main reason that the fruit is left to rot is that it’s a heck of a lot easier than trying to extract seeds from the fruit by hand. Why not let some friendly microorganisms handle it?

The seeds are then dried to stop the fermentation process and bagged into breathable sacks, like burlap, for transport around the world. For some reason at this point they are called beans, but, just like coffee beans, they are really the dried seed of a fruit. They bear little agricultural relation to true legumes, like, say, your average soybean.

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Cocoa beans, er, seeds. Whatever.

When the beans get sold to the chocolate maker – and this is where I step in – they have to be roasted in order to develop their flavor. This too is similar to their pseudo-beany cousins, coffee. For both beans, the roast drives off volatile flavors and moisture, removing alcohols and acids to quiet the sharp raw flavors into something warmer and less bitter. While raw coffee tastes rather green and grassy, like a bitter-acidic mealy unripe pea, cacao gets more of the flavor of a bitter-acidic fruit candy: its bright acids and volatile compounds give it cherry, sour apple, and even banana flavors. When roasted, the cocoa still retains some bitterness, but the acid tends to mellow out and the bean gets an earthier and distinctly chocolate flavor. This stage is not for the faint at heart: the best way to determine how long to roast the bean is to, at intervals, taste it. Raw. This is not quite as delightful as you might think: if you’ve ever had a very dark chocolate – say, 80% – you know that the less sugar there is in the bar, the more bitter. Imagine, then, having an almond-sized bite of acidic chocolate at 100% darkness – it can make your tastebuds go on strike. On the plus side, the roasting beans make your house smell like you’re baking an epic batch of brownies.

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Phantom brownies.

After roasting the bean, the thin shell on the outside becomes dry, flaky, and separates from the inside fairly easily. That shell has got to go, so the chocolate bean is passed through a mill. Large scale operations have a real mill to crack the beans: two rough rolling cylinders at just the right distance to shear off the shell without pulverizing it to dust. The best homespun solution is to use a “masticating juicer”, like a Champion juicer. These juicers have a cylinder with tiny teeth on them that “chews” fruits and vegetables in order to extract their juice. While amazingly good juicers – just throw whatever organic thing you want in ‘em and it’ll get the juice out – they work really well as a mill in this scenario too. Remove the filter screen that allows the juice to flow through while holding the pulp back, and you’ve got yourself a cocoa mill. In go the roasted beans.

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Before and after milling the beans.

Hang on, we’re still not done. We’re only interested in the inside of the bean, not the shell. This part is called the “nib”, and it’s where the good stuff is at. The shell is tough and fibrous, and has to go. The process of separating the shell from the nib is called winnowing – yep, just like threshed wheat fresh off of the stalk, the method for separating the light husk from the tasty inside is to use air currents to separate the more dense grain from the less dense chaff. In my setup, I use a hair dryer to blow away the shells as I stir the cracked beans in a bowl. I do this on the porch for ease of cleanup, which makes me wonder what the our neighbors think of us: stirring a bowl of phantom brownies covered in cocoa powder is not normal neighbor behavior. It’s a bit laborious, but works surprisingly well, as long as one is willing to cover everything nearby in a fine dust of cocoa shells.

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Vidal Sassoon: unknowingly providing chocolate making supplies since 2006

Still not done. At this point, the chocolate maker has to choose the proportion of different beans to include in the chocolate, similar to a winemaker selecting a proportion of varietals of different grapes to make a balanced wine. Single origin chocolates are very interesting things, and well worth studying on their own – for instance, I learned from this process that I most prefer the terroir (taste imparted from the soil and environment) of western South America, as it provides beans that have an earthy and almost minerally roundness. Beans from Africa tend to be more acidic and bright, and beans from Madagascar are like drinking grenadine while licking a 9 volt battery. Great chocolates are made by creating an assemblage of different beans to get the right flavor profile. Who knew that the “chocolate” flavor was so complex? Not me, before making my own.

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The chocolate components assembled and weighed.

In addition to the cocoa beans, typical ingredients of a bar of chocolate include sugar, cocoa butter, powdered milk, vanilla extract, salt, and soy lecithin. Sugar makes the chocolate less bitter and turns it into the sweet candy we love. The cocoa butter is the “matrix” of the chocolate: the raw structure that suspends the cocoa solids and holds everything together. Cocoa beans are essentially cocoa butter and cocoa powder, and the addition of some of the extracted cocoa butter allows the chocolate to have more structure and be less crumble-ly. Milk goes naturally with chocolate, but since milk is water based and chocolate is oil based, the milk has to be evaporated and powdered, or else the chocolate will “sieze”: clump into unappetizing, ruined clods. Vanilla, rather than being “anti chocolate”, goes great with chocolate and enhances its aromatic sweetness. Salt is included as a flavor enhancer – in small doses, it makes the chocolate taste more “chocolate-y”. The lecithin is an emulsifier: it allows water-soluble and non-water-soluble components to mix, the way soap cuts grease and allows it to mix with water. Since the chocolate is such a mixture of components in fat – the cocoa butter – the lecithin acts like social tension in a crowded elevator: evenly spacing out and distributing all of the assorted components.

In a commercial chocolate factory, the cocoa beans are ground into a viscous liquid called “cocoa liquor” and then mixed with the remaining ingredients. I don’t take this step at home: one of the main reasons for doing it is to liquify the beans so that they can be expeller-pressed to separate cocoa powder from cocoa butter, which is where it comes from for producing the bars. Since I source my cocoa butter along with my beans, this is extra work that I don’t want to do in an already exasperating process. The grinding we’re about to do works just fine on its own.

We’re still not done. Now it’s time to make the actual chocolate. The process involves grinding up the cocoa beans so fine that any residual particles are too small for your tongue to detect, which lends a smooth mouthfeel to the chocolate. To accomplish this, there is really no other option than to use a wet grinder or “melangeur“. A melangeur – which is French for “mixer”, though there is very little resemblance to your KitchenAid – is more or less a mill that can handle wet ingredients. The most traditional form is a pair of granite rollers in a bowl with a granite bottom. The bowl rotates, and the contents get ground between the wheels and the bowl to produce chocolate. Of all the specialized equipment one can get, this is the cannot-be-substituted, it-is-not-chocolate-without-it component that turns all your random bits into chocolate.

Fortunately, I have a tabletop version. Thank you, Chocolate Alchemy. Thank you, strange-project-enabling wife. Thank you, producers of ridiculously specific equipment.

Into the melangeur goes the sugar, cocoa butter, and a little of the beans. It’s best to start out with mostly cocoa butter to allow it to shear and liquify, and the sugar and beans help by adding abrasives. If one throws in all ingredients at once, one finds the melangeur does not turn. One need simply ask one’s past self how that turns out. Hypothetically.

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Loaded and ready to make chocolate.

After the contents are more liquid than solid, the nibs are added a little at a time to be ground and mixed with the rest of the contents. Then it’s just a matter of grinding them together.

For days.

What’s going on here is that we’re trying to pulverize the nibs, but we’re also shearing and mixing the contents as the nibs break down. In fact, there’s a separate term for the flavor refining that happens after the contents are fully mixed: it’s called “conching”, after the shell shape of the machines that originally performed this function – yet another chocolate-related term that makes little sense. Even though the taste of the chocolate changes here, the transformation is still more alchemy than chemistry and not well understood. From my experience, this is the step where any residual water is removed, and the bright and acidic volatiles are driven out of the chocolate. In fact, raising the lid of the mixer during conching will grant you a sharp acidic whiff of pungent air.

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Grind baby grind.

Finally, we have chocolate. But we’re not done. Naturally.

The chocolate at this point is out of temper: when you snap into a bar of chocolate, the chocolate has been heat treated to form just one crystalline structure: a strong one, which will allow you to hold on to a bar without it melting in your hand and give it a glossy, snappy feel. Tempering the chocolate is the process of selecting for the one crystalline structure to be present when the chocolate solidifies.

A note about the chemistry of crystals: substances that solidify in crystals can often do so in multiple configurations. The shape of the crystals has much to do with the properties of the substance. For instance, graphite and diamond are both pure carbon, but graphite is a soft powder and diamond is the hardest known natural substance. The difference is simply in their crystalline structure: graphite is made of sheets of carbon, where the molecules bind strongly in a horizontal plane but not vertically, which means that the sheets can slide over each other easily. Diamond is the near-optimum structure: each atom is connected in a triangular pyramid to its neighbors, which make it very, very strong in every direction.

It’s the stronger crystals that cocoa butter creates that we want in our chocolate. Out of the six crystalline structures we want – yes, there are six options to choose from – we have to exploit the temperature characteristics of the different forms to get the one we want. The strongest structures melt at the highest temperature, so the procedure is:

  1. Cool the warm chocolate down to where we know the strongest several structures are forming.
  2. Re-warm the chocolate just enough to leave the strong structures. Too cool, and we have multiple forms. Too hot, and we lose our stronger seed crystals as well as the weaker ones.
  3. When the chocolate cools, the seeded crystals will induce their neighbors to adopt the same structure, like a low-self-esteem family keeping up with the Joneses.

Delicate temperature control to within a few degrees of an entire batch of chocolate is very tricky. Direct heat can burn the chocolate, so most chefs use a double boiler or, believe it or not, a microwave. There are problems with both – a double boiler involves water and steam, which will sieze and ruin the whole batch of chocolate on contact. A microwave involves no water, but there are hot spots in every microwave that can burn points on the inside of the pool of chocolate, so one has to heat and stir in 5 second intervals to even out the temperature.

I’ve found the best approach is to carefully temper the chocolate over multiple cycles of warming and cooling to try to coax ever greater populations of the seed crystals to form. There are commercial machines that will temper chocolate by doing this very thing with no water or microwave. For a price. A large one.

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Or we could use a double boiler, a ten dollar thermometer, and a whisk.

Once this is done, then we’re ready to pour the chocolate into molds. This is pretty much what you’d expect. Liquid chocolate meets mold, cools down, we have hard chocolate.

And then, yes, finally, truly, there is only one step left: eat the chocolate.

This is one of those “don’t try this at home” things that only the really interested (or stupid, or both) should try: it’s expensive – each standard sized bar I produce would have to retail for around $8-$10 in order to cover capital, labor, and ingredients. It’s messy: chocolate dust everywhere, melted chocolate in your clothes, lots of equipment to clean. It requires some expensive stuff: we already had the juicer as an awesome gift from my brother-in-law, but the $300 melangeur was a new purchase. All of this just to make what you can buy at your neighborhood 7-11.

But the result is awesomely good, way better than anything at the Kwik-E-Mart. And the bragging rights among your foodie friends? Untouchable.

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Bonus points if your Enabler of Strange Projects buys you custom molds.

If you are curious, here is a typical recipe. I made this chocolate to bring to Tara Firma Farm on May 27, 2012 as my potluck contribution for their pig roast:

8 oz. Fair Trade and Organic Forastero beans from Ecuador
Earthy, round, and soft. A great solid flavor base.

8 oz. Fair Trade and Organic Forastero beans from Conacado CoOp – Dominican Republic
Earthy and buttery, with some cherry and pear flavor.

6 oz. Organic Criollo/Trinitario beans from Bolivia
Tobacco, smoke, coffee flavors that will help the earthy flavor but could be overpowering if overused.

4 oz. Fair Trade and Organic Criollo beans from Peru
Bright up front and fruity flavors, almost African in terroir.

6 oz. cocoa butter

1 lb. organic sugar

4 oz. organic powdered milk

1Tb. organic vanilla extract

1 tsp. salt

1/4 tsp. soy lecithin

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